시판 두부 제조 공정 중의 Microflora Profile 분석

Abstract

Microflora profiles including total bacteria, psychrophiles, and spore-forming bacteria in manufacturing process steps of tofu were analyzed to elucidate the cause of microbial contamination. The viable cell numbers of total bacteria in soybean and packed tofu were 4.75 and 2.53 log CFU/g, respectively. The viable cell number of psychrophiles in soybean was calculated to 3.55 log CFU/g, and reduced to 0.78 log CFU/g by heating during the soymilk preparation step, and was not detected in the final product. The viable cell numbers of spore-forming bacteria, the major bacteria in soymilk, in soybean and packed tofu were 1.75 and 0.58 log CFU/g, respectively. Total twenty nine genus and seventy species of bacteria were isolated and identified in the manufacturing process of tofu, from soybean to final packed tofu. The major bacteria existed in the soybean, soymilk, forming belt, sum-mul plate, knife, packed tofu before sterilization, and packed tofu after sterilization were identified as Bacillus spp., Lysinibacillus bronitoleran, Acinetobacter spp., Bacillus spp., Acinetobacter spp., Acinetobacter spp., Staphylococcus spp., respectively.